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Documentation Docs/en/reference/font-format/layout.md

Text Layout Contract

Generated reference. Do not edit directly. Update BuildTools/FontFormatInterface.json, then run python BuildTools/docs_font_format.py --write.

FontFlag values

Name	Value	Source behavior
`None`	`0x0000`	Applies no optional text-layout or glyph-rendering flags
`NoWrap`	`0x0001`	Truncates the remaining text at rectangle-width overflow instead of wrapping it
`TruncateLine`	`0x0002`	Skips overflowing glyphs through the next newline instead of wrapping the current line
`CenterX`	`0x0004`	Horizontally centers each rendered line within the target rectangle
`CenterY`	`0x0008`	Vertically centers the complete text block within the target rectangle
`AlignRight`	`0x0010`	Right-aligns each rendered line within the target rectangle
`AlignBottom`	`0x0020`	Aligns the text block to the bottom and makes SkipLines count from the trailing lines
`KeepTail`	`0x0040`	Renders the tail of a text block that is taller than the target rectangle
`NoColorize`	`0x0080`	Removes inline color tags while retaining the supplied base text color
`Justify`	`0x0100`	Distributes extra spacing between words to fill each line’s target width
`Bordered`	`0x0200`	Uses the bordered or outlined font-texture variant for glyph rendering

Layout rules

Stable ID	Rule	Requirement	Why	Source
`font-format.layout.text-format`	TextFormat value	Pass a Font slot, FontFlag bitmask, and nonnegative SkipLines count as TextFormat.	The exported value type is a fixed 12-byte layout consumed by measurement and drawing.	Source/Client/FontManager.h
`font-format.layout.wrap-overflow`	Width overflow and wrapping	With finite width, default layout wraps at the latest space or tab and inserts a line break before an overlong token when no break point exists.	Layout mutates its cached text copy to establish line boundaries without changing the caller’s source string.	Source/Client/FontManager.cpp
`font-format.layout.no-wrap-and-truncate`	NoWrap and TruncateLine	NoWrap ends draw text at the first width overflow; TruncateLine removes overflowing glyphs through the next authored newline.	These flags intentionally choose different loss behavior and should not be treated as synonyms.	Source/Client/FontManager.cpp
`font-format.layout.horizontal-alignment`	Horizontal alignment	CenterX and AlignRight position each line independently inside the supplied rectangle; do not combine contradictory alignment flags.	The initial and every post-newline X coordinate are recalculated from that line’s measured width.	Source/Client/FontManager.cpp
`font-format.layout.vertical-alignment`	Vertical alignment	CenterY centers the visible block and AlignBottom places it against the rectangle bottom using LineHeight and YAdvance.	Vertical placement depends on the number of lines that fit, not the total source-string byte length.	Source/Client/FontManager.cpp
`font-format.layout.skip-lines-and-tail`	SkipLines and KeepTail	SkipLines removes leading lines by default and trailing lines with AlignBottom; KeepTail discards leading overflow so the newest visible lines remain.	These mechanisms serve pagination and log-tail behavior but use different counters and overflow conditions.	Source/Client/FontManager.cpp
`font-format.layout.justification`	Justification	Justify distributes remaining finite rectangle width over breakable spaces on wrapped non-skipped lines.	Tabs are fixed at four SpaceWidth units and are not justification opportunities.	Source/Client/FontManager.cpp
`font-format.layout.utf8-and-missing-glyphs`	UTF-8 and missing glyphs	Author every required Unicode codepoint; invalid UTF-8 and absent glyphs consume no glyph width and render no fallback symbol.	The layout maps invalid sequences to codepoint zero and unknown codepoints to zero advance, while drawing skips missing map entries.	Source/Client/FontManager.cpp
`font-format.layout.measurement`	Measurement matches layout	Use Game.GetTextInfo and related line helpers with the same rectangle and TextFormat used for drawing, but do not infer draw-only NoWrap truncation from measurement.	Measurement and drawing share GetOrFormat, skips, line metrics, and bind-time scale; NoWrap truncation is intentionally gated to Draw mode.	Source/Client/FontManager.cpp, Source/Scripting/ClientGlobalScriptMethods.cpp